This scanning electron micrograph (SEM) revealed some of the ultrastructural morphology displayed on the dorsal exoskeletal surface of a bedbug, Cimex lectularius. Note the numbers of what appear to be hairs, but are actually known as setae, which are sensorial in nature, and are composed of chitin, as is the entire exoskeleton.Chitin is a molecule made up of bound units of acetylglucosamine, joined in such a way as to allow for increased points at which hydrogen bonding can occur. In this wa